Comment

Comment by Meir Lazar on October 31, 2012 at 11:20am

During the storm, I got a crazy bug in my head to start a new indoor 4'x4' ebb & flow bioponic system. The media is coconut coir with hydroton and perlite (lots of surface area for biological action. I brought in some of my plants and seeded some greens.

Comment by Eric Warwick on June 16, 2012 at 1:26am

Interesting Vlad, once again you've made me a little smarter! By the way, I meant that people should still substitute K. I'll be in a college level chemistry class next year--so I'll make sure to dump everything I learn there onto the forum.

Comment by Vlad Jovanovic on June 16, 2012 at 1:19am

Erik, just don't discount the massive amounts K that many fruiting plants need. (Especially cucurbits...but any of your "P-powered flowers" that you want to grow into harvest-able fruit, is going to take a significant amount of K)...Now I believe that supplementing your own diet with K (and cutting back on the Na...which I've come to find is pretty easy to do, once you stop eating processed crap) is a good idea...if not for your plants, then at least for yourself. Luckily, amending K in a bio-ponic system is relatively easy...

Iron however, without resorting to Fe-chelate products is not so easy. I like the RSG filter idea, but the biggest problem I see there is that once your 'iron rich' (Fe2+) water trickles out of your RSG filter and enters into an oxygen rich environment (like our system water), depending on your temps and pH, it can take only seconds (time) for the Fe2+ to revert back to Fe3+. Which wouldn't be enough time for your plants to use it. That being said, it is my belief that this needs not be the 'fatal flaw' in such a design, and that this can in all probability be mitigated to a degree that would allow your plants to use the iron. Organic acids, like humic acids and tannins have the ability to bind (chelate) Fe2+ and keep it from wanting to transition to Fe3+. Like a "time-buffer" for transitional metals. It turns out this is exactly how people made Iron Gall Ink for centuries (if not millenia). Many AP and/or various bio-ponic systems probably meet the criteria for this iron "time-buffer". Seems like a 'science project' worth investigating...

Comment by Eric Warwick on June 15, 2012 at 10:34pm

TCLynx, the way I see it is that plants need the iron ion and if you do manage to pee it out then  it would not be in usable form (this comes from knowledge of fish process--feeding your fish spinach won't help). Also, most of us are deficient in iron, so eating significant amounts would not have much effect. (Still, eating more spinach is probably a good idea.) I think it would be  easier to grow non-fruiting plants, but if you've got ample phosphorus then why stick to leafy greens?  

Comment by TCLynx on June 15, 2012 at 8:41pm

sodium and potassium are somewhat interchangeable in many processes in the human body so if you were to reduce your sodium intake in preference to potassium chloride (salt substitute) you might have a little more potassium in your pee but I expect the change will be minimal, as Eric says, we sweat alot of it out instead of peeing it.  Pee is generally quite amply supplied with Nitrogen and Phosphorus and Potassium (K) as well as iron are likely elements to need to supplement in pee ponics just like in aquaponics.  No I have heard of people upping their iron intake to improve a pee ponics system by eating lots of extra spinach but I don't know how effective it was.  Usually easier to supplement a bit of seaweed extract and chelated iron.

Comment by Eric Warwick on June 15, 2012 at 7:32pm

*K instead of N--pee is full of N (NH4=pee).

Comment by Eric Warwick on June 15, 2012 at 7:31pm

Meir, the Nitrogen (protiens) and Phosphorous (ATP--needed in powering your body) will be used up for building muscle, in the case of N, and P will decrease bone density. You can't bring more N or P into your pee (not a rhyme, but it might as well be). Also, I think you mean K or Potassium, which I guess you could pee out, after sweating it out and using more of it. In any case, adding  the special K is not going to be good for your bodies balance.  

Comment by Meir Lazar on June 15, 2012 at 10:49am

Thanks everyone. I'm thinking I might experiment with either wood ash, bone meal or ban guano. Not sure which is truest to the peeponic philosophy (if there is one). Of course another way would be to simply increase the PK in my diet. I just don't want a build-up of salts or nutrients the way hydroponics can, since I want to maintain a close-loop system.

Comment by Vlad Jovanovic on June 11, 2012 at 1:16pm

Oh yeah, if you do decide to go the route of home made potassium from ashes...here's the best I have it figured without using any fancy ultra expensive probes or testing equipment... http://aquaponicscommunity.com/profiles/blogs/determining-homemade-...

You can probably skip all that crap in the first three paragraphs you already know and go right to the formula...

Comment by Vlad Jovanovic on June 11, 2012 at 1:09pm

The NPK value of human urine is either 11-1-2 or 15-1-2 depending on which studies you read...TC is right about the phosphorous for flowering and potassium for fruiting...

The ashes of hardwood trees are a good source of potassium, but will definitely raise your pH...so you could sorta use it as a buffer. A little seems to go a long way...I have a wood burning stove and lots of forest, so this was a logical choice for me... 

Phosphorus, if it ever actually becomes a problem can be added in a whole host of ways...Rock of Phosphate being more quickly bio-available, I think, than the aged, crushed, ground up bones of animals (plenty of that in my neighborhood too, an old brass hand turned coffee grinder works wonders after you put the bone in cloth and pulverize them with a big hammer first...then comes the sifting). I guess if you live someplace normal, you could just buy bone-meal.

If you've got tomatoes starting to go into flowering, watch your ammonia levels... Although when in initial vegetative stage , the NH4-N form (ammonia) is more readily utilized, thereby benefiting early plant growth and development... when the tomato plant enters its reproduction stage, NH4 can adversely affect both plant growth and fruit yield as well as increasing the incidence of blossom-end rot (BER) in fruit, a phenomenon that has been frequently observed and reported. In a nutrient solution if the NH4 percentage is greater than 25% of total N, (as opposed to nitrates) there is a decrease in the number and fresh weight of fruit. In addition, the number of fruit with BER increases...Seems that too much nitrogen of any type though will pull a number on a tomato plant's ability to uptake calcium, resulting in BER. And foliar feeding the Ca will be useless... This is according to a well respected hydroponicist (that might not actually be a word) PhD in Agronomy, Mr. Jones Benton Jr...A guy whose studies, books, and articles I have come to adore and respect. He's a tomato guy...So make sure your biofilter is on the up and up. This is one piece of info I did not feel the need to test out for myself. 

So maybe slow up on the hummonia and find a way to add P-K in a way that you are comfortable with and/or philosophically in tune with...or whatever the case may be.

For every damned thing you could ever want to know about cucumbers and then some, check out Papadopoulos (1994) from the Harrow Reaearch Station in Ontario.

You should have no problems pilfering these gems from the Net.

This is all classic hydro stuff, but still basically applies even if your inputs are 'organic'...or a mixture of mineral salts and organic or whatever. Measuring inputs, figuring percentages, strengths of whatever in solution becomes half guesstimation based on science and formulas, precise measuring and a good pH meter...and half mojo-voodoo...Suits me just fine. So far so good. I'm sure someone else has it figured out much better/more precisely than me though. Half this crap, even if I knew the answer was written in plain black and white somewhere (as most of it probably is) I still wouldn't want to read it...Takes the fun out of feeling like Columbus at times 

• ‹ Previous
• 1
• 2
• 3
• 4
• 5
• …
• 13
• Next ›
• Page